/*
 * Copyright (c) 2007, 2015, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
/*
 * Copyright 2001-2004 The Apache Software Foundation.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: ApplyImports.java,v 1.2.4.1 2005/09/13 12:22:02 pvedula Exp $
 */

package com.sun.org.apache.xalan.internal.xsltc.compiler;

import java.util.Enumeration;

import com.sun.org.apache.bcel.internal.generic.ConstantPoolGen;
import com.sun.org.apache.bcel.internal.generic.INVOKESPECIAL;
import com.sun.org.apache.bcel.internal.generic.INVOKEVIRTUAL;
import com.sun.org.apache.bcel.internal.generic.InstructionList;
import com.sun.org.apache.bcel.internal.generic.NEW;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.ClassGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.MethodGenerator;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Type;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.TypeCheckError;
import com.sun.org.apache.xalan.internal.xsltc.compiler.util.Util;

final class ApplyImports extends Instruction {

  private QName _modeName;
  private int _precedence;

  public void display(int indent) {
    indent(indent);
    Util.println("ApplyTemplates");
    indent(indent + IndentIncrement);
    if (_modeName != null) {
      indent(indent + IndentIncrement);
      Util.println("mode " + _modeName);
    }
  }

  /**
   * Returns true if this <xsl:apply-imports/> element has parameters
   */
  public boolean hasWithParams() {
    return hasContents();
  }

  /**
   * Determine the lowest import precedence for any stylesheet imported
   * or included by the stylesheet in which this <xsl:apply-imports/>
   * element occured. The templates that are imported by the stylesheet in
   * which this element occured will all have higher import precedence than
   * the integer returned by this method.
   */
  private int getMinPrecedence(int max) {
    // Move to root of include tree
    Stylesheet includeRoot = getStylesheet();
    while (includeRoot._includedFrom != null) {
      includeRoot = includeRoot._includedFrom;
    }

    return includeRoot.getMinimumDescendantPrecedence();
  }

  /**
   * Parse the attributes and contents of an <xsl:apply-imports/> element.
   */
  public void parseContents(Parser parser) {
    // Indicate to the top-level stylesheet that all templates must be
    // compiled into separate methods.
    Stylesheet stylesheet = getStylesheet();
    stylesheet.setTemplateInlining(false);

    // Get the mode we are currently in (might not be any)
    Template template = getTemplate();
    _modeName = template.getModeName();
    _precedence = template.getImportPrecedence();

    // Get the method name for <xsl:apply-imports/> in this mode
    stylesheet = parser.getTopLevelStylesheet();

    parseChildren(parser);  // with-params
  }

  /**
   * Type-check the attributes/contents of an <xsl:apply-imports/> element.
   */
  public Type typeCheck(SymbolTable stable) throws TypeCheckError {
    typeCheckContents(stable);              // with-params
    return Type.Void;
  }

  /**
   * Translate call-template. A parameter frame is pushed only if
   * some template in the stylesheet uses parameters.
   */
  public void translate(ClassGenerator classGen, MethodGenerator methodGen) {
    final Stylesheet stylesheet = classGen.getStylesheet();
    final ConstantPoolGen cpg = classGen.getConstantPool();
    final InstructionList il = methodGen.getInstructionList();
    final int current = methodGen.getLocalIndex("current");

    // Push the arguments that are passed to applyTemplates()
    il.append(classGen.loadTranslet());
    il.append(methodGen.loadDOM());
    il.append(methodGen.loadIterator());
    il.append(methodGen.loadHandler());
    il.append(methodGen.loadCurrentNode());

    // Push a new parameter frame in case imported template might expect
    // parameters.  The apply-imports has nothing that it can pass.
    if (stylesheet.hasLocalParams()) {
      il.append(classGen.loadTranslet());
      final int pushFrame = cpg.addMethodref(TRANSLET_CLASS,
          PUSH_PARAM_FRAME,
          PUSH_PARAM_FRAME_SIG);
      il.append(new INVOKEVIRTUAL(pushFrame));
    }

    // Get the [min,max> precedence of all templates imported under the
    // current stylesheet
    final int maxPrecedence = _precedence;
    final int minPrecedence = getMinPrecedence(maxPrecedence);
    final Mode mode = stylesheet.getMode(_modeName);

    // Get name of appropriate apply-templates function for this
    // xsl:apply-imports instruction
    String functionName = mode.functionName(minPrecedence, maxPrecedence);

    // Construct the translet class-name and the signature of the method
    final String className = classGen.getStylesheet().getClassName();
    final String signature = classGen.getApplyTemplatesSigForImport();
    final int applyTemplates = cpg.addMethodref(className,
        functionName,
        signature);
    il.append(new INVOKEVIRTUAL(applyTemplates));

    // Pop any parameter frame that was pushed above.
    if (stylesheet.hasLocalParams()) {
      il.append(classGen.loadTranslet());
      final int pushFrame = cpg.addMethodref(TRANSLET_CLASS,
          POP_PARAM_FRAME,
          POP_PARAM_FRAME_SIG);
      il.append(new INVOKEVIRTUAL(pushFrame));
    }
  }

}
